There are plenty of "couplets done right" that were engineered decades ago to take advantage of narrow inner city streets; or more recently in Albany and Philomath.

When done right, traffic moves more smoothly, it's easier to get "across" the street as there's now a natural median between the two directions of travel, and it allows for narrower streets in the inner city (two two lane streets, instead of one five lane street).

When done wrong...well...Portland can show you that. Has the City screwed up the Stark/Washington couplet yet, or the Foster/Woodstock couplet?

"do things to slow down the cars."

Like becoming mobile speed bumps.

The obsession with narrowing lanes in urban areas is quite dangerous because it increases the risk for head-collisions and otherwise. Back east here, less than a mile from my home, an oncoming garbage truck traveling into the morning sun sliced off the side of a school bus in a too narrow lane killing two elementary school students a few years back. Yet in urban planning fantasy land narrow lanes are supposedly safe. Yuck!

The thing that amazes me about artificially engineered traffic congestion is, how can it not lead to increased emissions and increased fuel consumption, the latter being a gift to the oil companies?

I can hardly wait for my neighborhood to be forceably reengineered into a segregated 'live/work/play in walking/biking distance' neighborhood...

Oh, but wait, I just got laid off and the only other job I can find is miles and miles away, oh well, I can work from home...

Oh, but wait, that didn't work out for long because working from home means anyone else on the internet can do my job from some far away low wage 3rd world country...

Oh well, I'm sure I can live in my cramped condo box cell where classic craftsman homes were demolished and pay my mortgage by working at the coffee shop or boutique resale shop around the corner, right?

Or, I can be a Tri-Met supporter and spend hours and hours a day riding snail-rail and picturesque trolley cars like in simpler days of old...

Oh, but wait... it just ran over somebody and the line is down for hours!

I can imagine that 39th/Chavez near my house (south of I-84) might actually run smoother if there were one nice wide lane in each direction and a left turn lane in the middle. Right now people shift lanes a lot to get around cars stopped to turn left, and then have to get in the center lanes again to get around the Glisan traffic circle.

But ride a bike on 39th if they put a bike lane there? No way. I ride quite a bit in the city, and vastly prefer riding the non-arterial designated bike routes -- N/S along 41st, along E/W along Tillamook (instead of the bike lane on Broadway).

Sarah,
You bring up an interesting subject...
The traffic circle at Glisan and 39th has been made dysfunctional with the stop signs and having only the center lane going on through, resulting in 50% of the traffic having to make a last minute lane change. That's not how they're done in Europe nor around Clackamas or Washington counties, where they're an effective means of keeping traffic moving in all directions.

And WHY would anyone want to bike down 39th when there is a bike route running parallel 2 blocks away?

One has to question the motives behind these planning decisions that have the appearance of being incredibly stupid.